Venetoclax-based non-intensive induction followed by allogenic stem-cell transplantation in elderly acute myeloid leukemia patients with adverse cytogenetics.

INTRODUCTION: Elderly acute myeloid leukemia (AML) patients with poor-risk cytogenetics have a poor outcome with intensive chemotherapy (IC). While Venetoclax (VEN) has changed the outcomes of elderly unfit patients treatment, it is unknown whether it could be effective in poor-risk cytogenetics 60-75 years old patients. MATERIALS AND METHODS: We included 60-75-year-old AML patients eligible to allogenic stem cell transplantation (allo-SCT) treated with VEN (combined with azacitidine or with Cladribin and Aracytine) at Institut Paoli Calmettes, between 2020 and 2023 and compared this cohort with patients treated by IC between 2010 and 2019. RESULTS: Twenty six patients were treated with VEN (17 in combination with azacitidine and 9 with Cladribin and Aracytine) and 90 were treated with IC. Thirteen patients (50%) had a TP53 mutation. The median time for leucocyte and platelet counts recovery was 26 days (range 0-103) and 26 days (range, 0-63). The median duration of the first hospitalization was 32 days (ranges, 7-79). The composite response rate was 69% (CR = 50%, CRi = 4%, MLFS = 15%). Allo-SCT could be performed in 42% of cases. Median overall survival (OS) was 7.9 months (20.9 months in the group of patients who transitioned to allo-SCT). We found no difference with the historical cohort of patients treated with IC except a trend toward less lower and upper tract gastro-intestinal (GI) tract infections in the VEN group (respectively 8% vs 26%, p = .06; and 0% vs. 13% p = .06). CONCLUSION: VEN-based treatment was found to be effective in high risk AML can be considered as an alternative to IC in patients aged 60-75 with adverse cytogenetics.

Outcomes of acute myeloid leukemia patients who responded to venetoclax and azacitidine and stopped treatment.

Venetoclax-azacitidine is the standard of treatment for unfit acute myeloid leukemia patients. In the VIALE-A study, treatment was given until progression but there are no data on its optimal duration for responding patients who do not tolerate indefinite therapy. We retrospectively analyzed the outcome of patients who discontinued venetoclax or venetoclax-azacitidine due to poor tolerance. Sixty-two newly diagnosed (ND) AML patients and 22 patients with morphological relapse or refractory AML were included. In the ND cohort (n = 62), 28 patients stopped venetoclax and azacitidine and 34 patients continued azacitidine monotherapy. With a median follow-up of 23 months (IQR, 20-32), median overall survival and treatment-free survival were 44 (IQR, 16-NR) and 16 (IQR, 8-27) months, respectively. Patients who stopped both treatments and those who continued azacitidine monotherapy had the same outcomes. Negative minimal residual disease was associated with a 2-year treatment-free survival of 80%. In the RR cohort (n = 22), median overall survival and treatment-free survival were 19 (IQR, 17-31) and 10 (IQR, 5-NR) months, respectively. Prior number of venetoclax-azacitidine cycles and IDH mutations were associated with increased overall survival. The only factor significantly impacting treatment-free survival was the number of prior cycles. This study suggests that patients who discontinued treatment in remission have favorable outcomes supporting the rationale for prospective controlled trials.

Regulation of the positive transcriptional effect of PLZF through a non-canonical EZH2 activity.

The transcription factor PLZF (promyelocytic leukemia zinc finger protein) acts as an epigenetic regulator balancing self-renewal and differentiation of hematopoietic cells through binding to various chromatin-modifying factors. First described as a transcriptional repressor, PLZF is also associated with active transcription, although the molecular bases underlying the differences are unknown. Here, we reveal that in a hematopoietic cell line, PLZF is predominantly associated with transcribed genes. Additionally, we identify a new association between PLZF and the histone methyltransferase, EZH2 at the genomic level. We find that co-occupancy of PLZF and EZH2 on chromatin at PLZF target genes is not associated with SUZ12 or trimethylated lysine 27 of histone H3 (H3K27me3) but with the active histone mark H3K4me3 and active transcription. Removal of EZH2 leads to an increase of PLZF binding and increased gene expression. Our results suggest a new role of EZH2 in restricting PLZF positive transcriptional activity independently of its canonical PRC2 activity.

Efficacy of chemotherapy or chemo-anti-PD-1 combination after failed anti-PD-1 therapy for relapsed and refractory Hodgkin lymphoma: A series from Lysa centers.

Anti-PD-1 therapy provides high response rates in Hodgkin lymphoma (HL) patients who have relapsed or are refractory (R/R) to autologous stem cell transplantation (ASCT) and brentuximab vedotin (BV), but median progression free survival (PFS) is only one year. The efficacy of treatment following anti-PD-1 is not well known. We retrospectively investigated the efficacy of salvage therapies for unsatisfactory response to anti-PD-1 therapy, assessed by PET-CT according to the Lugano criteria, in 30 R/R HL patients. Patients were highly pre-treated before anti-PD-1 (70% received ASCT and 93% BV). Unsatisfactory responses to anti-PD1 therapy were progressive disease (PD) (n=24) and partial response (PR) (n=6). For the 24 PD patients, median anti-PD-1 related PFS was 7.5 months (95%CI, 5.7-11.6); 17 received subsequent CT alone (Group 1) and 7 received CT in addition to anti-PD-1 (Group 2). 16/24 patients (67%) obtained an objective response. In the 15 patients treated with the same CT, twelve obtained PR or complete response (CR). In Group 1, there were 7 CR (41%), 3 PR (18%), and 7 PD (41%). In Group 2, there were 4 CR (57%), 2 PR (29%), and 1 SD (14%). No unexpected toxicity was observed. Six patients who achieved response proceeded to allogeneic SCT. With a median follow-up of 12.1 months (7-14.7), the median PFS following the initiation of CT was 11 months (95%CI, 6.3; not reached) and the median of overall survival was not reached. These observations in highly pre-treated HL patients suggest that anti-PD-1 therapy might re-sensitize tumor cells to CT. This article is protected by copyright. All rights reserved.

Bendamustine-based conditioning prior to autologous stem cell transplantation (ASCT): Results of a French multicenter study of 474 patients from LYmphoma Study Association (LYSA) centers.

Carmustine shortage has led to an increase use of alternative conditioning regimens prior to autologous stem cell transplantation for the treatment of lymphoma, including Bendamustine-based (BeEAM). The aim of this study was to evaluate the safety of the BeEAM regimen in a large cohort of patients. A total of 474 patients with a median age of 56 years were analyzed. The majority of patients had diffuse large B-cell lymphoma (43.5%). Bendamustine was administered at a median dose of 197 mg/m2 /day (50-250) on days-7 and -6. The observed grade 1-4 toxicities included mucositis (83.5%), gastroenteritis (53%), skin toxicity (34%), colitis (29%), liver toxicity (19%), pneumonitis (5%), and cardiac rhythm disorders (4%). Nonrelapse mortality (NRM) was reported in 3.3% of patients. Acute renal failure (ARF) was reported in 132 cases (27.9%) (G ≥2; 12.3%). Organ toxicities and death were more frequent in patients with post conditioning renal failure. In a multivariate analysis, pretransplant chronic renal failure, bendamustine dose >160 mg/m2 and age were independent prognostic factors for ARF. Pretransplant chronic renal failure, hyperhydration volume, duration of hyperhydration, and etoposide dose were predictive factors of NRM. A simple, four-point scoring system can stratify patients by levels of risk for ARF and may allow for a reduction in the bendamustine dose to avoid toxicity. Drugs shortage may have dangerous consequences. Prospective, comparative studies are needed to confirm the toxicity/efficacy extents from this conditioning regimen compared to other types of high dose therapy.

Allogeneic stem cell transplantation for advanced cutaneous T-cell lymphomas: a study from the French Society of Bone Marrow Transplantation and French Study Group on Cutaneous Lymphomas.

The treatment of advanced stage primary cutaneous T-cell lymphomas remains challenging. In particular, large-cell transformation of mycosis fungoides is associated with a median overall survival of two years for all stages taken together. Little is known regarding allogeneic hematopoietic stem cell transplantation in this context. We performed a multicenter retrospective analysis of 37 cases of advanced stage primary cutaneous T-cell lymphomas treated with allogeneic stem cell transplantation, including 20 (54%) transformed mycosis fungoides. Twenty-four patients (65%) had stage IV disease (for mycosis fungoides and Sézary syndrome) or disseminated nodal or visceral involvement (for non-epidermotropic primary cutaneous T-cell lymphomas). After a median follow up of 29 months, 19 patients experienced a relapse, leading to a 2-year cumulative incidence of relapse of 56% (95%CI: 0.38-0.74). Estimated 2-year overall survival was 57% (95%CI: 0.41-0.77) and progression-free survival 31% (95%CI: 0.19-0.53). Six of 19 patients with a post-transplant relapse achieved a subsequent complete remission after salvage therapy, with a median duration of 41 months. A weak residual tumor burden before transplantation was associated with increased progression-free survival (HR=0.3, 95%CI: 0.1-0.8; P=0.01). The use of antithymocyte globulin significantly reduced progression-free survival (HR=2.9, 95%CI: 1.3-6.2; P=0.01) but also transplant-related mortality (HR=10(-7), 95%CI: 4.10(-8)-2.10(-7); P<0.001) in univariate analysis. In multivariate analysis, the use of antithymocyte globulin was the only factor significantly associated with decreased progression-free survival (P=0.04). Allogeneic stem cell transplantation should be considered in advanced stage primary cutaneous T-cell lymphomas, including transformed mycosis fungoides.

Brentuximab vedotin followed by allogeneic transplantation as salvage regimen in patients with relapsed and/or refractory Hodgkin's lymphoma.

Patients with relapsed or refractory Hodgkin lymphoma (RR-HL) have poor outcomes. Brentuximab vedotin (BV), an antibody-drug conjugate comprising an anti-CD30 antibody conjugated to the potent anti-microtubule agent, monomethyl auristatin E, induces high tumour responses with moderate adverse effects. In a retrospective study, we describe objective response rates and subsequent allogeneic stem cell transplantation (allo-SCT) in patients with RR-HL treated by BV in a named patient program in two French institutions. Twenty-four adult patients with histologically proven CD30(+) RR-HL treated with BV were included from July 2009 to November 2012. Response to BV treatment was evaluated after four cycles. Eleven patients were in complete response (45.8%), while five patients were in partial response (20.8%), with an overall response rate of 66.6%. Eight patients failed to respond to BV (33.3%). All of the responding patients could receive consolidation treatment after BV: three patients underwent autologous stem cell transplantation (auto-SCT), three patients received a tandem auto-SCT/allo-SCT, nine patients received allo-SCT and one patient was treated with donor lymphocyte infusion. We found no treatment-related mortality at day 100 among the 12 patients who underwent BV following by allogeneic transplantation. With a median follow-up of 20 months (range 10.5-43.2), none of them relapsed or died. BV followed by allo-SCT represents an effective salvage regimen in patients with RR-HL.

Venetoclax Resistance in Acute Myeloid Leukemia.

Venetoclax is a BH3-mimetics agent interacting with the anti-apoptotic protein BCL2, facilitating cytochrome c release from mitochondria, subsequent caspases activation, and cell death. Venetoclax combined with azacitidine (VEN-AZA) has become a new standard treatment for AML patients unfit for intensive chemotherapy. In the phase III VIALE-A study, VEN-AZA showed a 65% overall response rate and 14.7 months overall survival in comparison with 22% and 8 months in the azacitidine monotherapy control arm. Despite these promising results, relapses and primary resistance to venetoclax are frequent and remain an unmet clinical need. Clinical and preclinical studies have been conducted to identify factors driving resistance. Among them, the most documented are molecular alterations including IDH, FLT3, TP53, and the newly described BAX mutations. Several non-genetic factors are also described such as metabolic plasticity, changes in anti-apoptotic protein expression, and dependencies, as well as monocytic differentiation status. Strategies to overcome venetoclax resistance are being developed in clinical trials, including triplet therapies with targeted agents targeting IDH, FLT3, as well as the recently developed menin inhibitors or immunotherapies such as antibody-drug conjugated or monoclonal antibodies. A better understanding of the molecular factors driving venetoclax resistance by single-cell analyses will help the discovery of new therapeutic strategies in the future.

Caspase-2 protects against ferroptotic cell death.

Caspase-2, one of the most evolutionarily conserved members of the caspase family, is an important regulator of the cellular response to oxidative stress. Given that ferroptosis is suppressed by antioxidant defense pathways, such as that involving selenoenzyme glutathione peroxidase 4 (GPX4), we hypothesized that caspase-2 may play a role in regulating ferroptosis. This study provides the first demonstration of an important and unprecedented function of caspase-2 in protecting cancer cells from undergoing ferroptotic cell death. Specifically, we show that depletion of caspase-2 leads to the downregulation of stress response genes including SESN2, HMOX1, SLC7A11, and sensitizes mutant-p53 cancer cells to cell death induced by various ferroptosis-inducing compounds. Importantly, the canonical catalytic activity of caspase-2 is not required for its role and suggests that caspase-2 regulates ferroptosis via non-proteolytic interaction with other proteins. Using an unbiased BioID proteomics screen, we identified novel caspase-2 interacting proteins (including heat shock proteins and co-chaperones) that regulate cellular responses to stress. Finally, we demonstrate that caspase-2 limits chaperone-mediated autophagic degradation of GPX4 to promote the survival of mutant-p53 cancer cells. In conclusion, we document a novel role for caspase-2 as a negative regulator of ferroptosis in cells with mutant p53. Our results provide evidence for a novel function of caspase-2 in cell death regulation and open potential new avenues to exploit ferroptosis in cancer therapy.